It is well known how to provide sorting systems for sorting out defective fruits and vegetables as they are being moved on a conveyor belt. Such systems might typically include a scanning camera, which on a line by line basis, senses an objectionable variation in shade and then through an integration process, determines whether or not this item or portion of item should be eliminated or sorted. Many times these systems must be backed up by a manual means where the vision of an actual person is utilized.
With respect to sorting on the basis of color variations, this has been thought to be so complicated that there are no practical techniques available. The major difficulty in this field is, of course, processing of pixel information on an online basis and in a reliable and error-free manner. In other words, when sorting or rejecting undesirable items, it is uneconomical to either oversort (rejecting good items) or undersort (allowing objectionable items to pass).